One method of dealing with excess noise generated by a specific source is to treat the noise at the source. This is typically accomplished by adding acoustic damping structures (acoustic treatments) to the structure surrounding the noise source. One particularly problematic noise source is the jet engines used on most passenger aircraft.
Open cell honeycomb core is a popular material for use in aircraft and aerospace vehicles because it is relatively strong and lightweight. For acoustic applications, a goal has been to incorporate acoustic material into the honeycomb structure. For instance, historically, acoustic material having a flange portion has been inserted into the honeycomb cells. The flange portion is substantially thicker than the acoustic material and provides an anchoring surface that is used to attach the acoustic material to the walls of the honeycomb. These flanged elements are initially held in place within the cells by frictional locking between the anchoring surface and the cell walls. This frictional locking is sufficient to keep the flanged elements in position until they are permanently bonded in place with an adhesive. Often times, capillary wetting is then used to integrate adhesive into the acoustic material then cured to secure the flanged element to the honeycomb wall. It would be beneficial to reduce the need for the additional processing steps utilized in this procedure. Also, it would be beneficial to produce an acoustic treatment material that does not require an anchoring surface/material that is separate from and/or have different properties than the acoustic material.